[Fortran]Multiplying Matrices Using dgemm

I do not know where to put this topic.However, I would like to multiply two arrays in Fortran using DGEMM (BLAS procedure).I have written a simple program:[code]program matrix implicit none double precision mac(m,n),mac2(n,k),mac3(m,k) integer R,L integer m,n,k

I get this result:[code]Matrix C: 29.00000000000000 0.0000000000000000 0.0000000000000000 36.00000000000000 0.0000000000000000 0.0000000000000000 27.00000000000000 7.2315834086755357E-308 0.0000000000000000 34.00000000000000 1.0037966311151816E-317 0.0000000000000000 Segmentation fault[/code]Do any of you have experience with Fortran and Blas and can point where is mistake?